Extended SOC 1980 codes
extend_standard_soc1980_codes.RdTakes valid 1980 standardized codes (the ones in the book) and extends them so that unit codes are always the most detailed (even if it is exactly the same as the parent code.)
extend_standard_soc1980_codes.RdTakes valid 1980 standardized codes (the ones in the book) and extends them so that unit codes are always the most detailed (even if it is exactly the same as the parent code.)